Structural Heart Issues in Dextrocardia: Situs Type Matters

摘要

Background: Patients who are diagnosed with dextrocardia, a rare congenital heart condition in which the heart points toward the right side of the chest, need their specific situs classification (eg, solitus, inversus, ambiguus) ascertained to optimize their care and outcomes. In this report, we discuss the perioperative anesthetic management of a patient presenting with dextrocardia.Case Report: A 44-year-old African American female with a history of hypertension, hyperlipidemia, gastroesophageal reflux disease, and diabetes mellitus type 2 was admitted for shortness of breath, dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea. The patient had been diagnosed with dextrocardia in 2003 at an outside hospital and was asymptomatic prior to this presentation. Chest x-ray revealed bilateral perihilar vascular congestion with bibasilar atelectasis and suspected small bilateral pleural effusions consistent with new-onset congestive heart failure. Preoperative 2-dimensional transthoracic echocardiography revealed an ostium secundum–type atrial septal defect (ASD) with mild left-to-right atrial shunting. The patient's ASD was repaired using a pericardial patch.Conclusion: The anesthetic management of patients presenting with dextrocardia is complex. Preoperative cardiac transthoracic echocardiography can identify cardiac lesions or aberrant anatomy associated with dextrocardia. Proper placement of electrocardiogram electrodes is necessary to avoid false-positive results for perioperative ischemia. Central line access must be adjusted to anatomic variations. Clinicians should have high suspicion for associated pulmonary hypertension and should limit sedatives preoperatively to minimize the cardiovascular effects of hypoxia and/or hypercarbia on the pulmonary vasculature. Finally, high clinical suspicion for respiratory complications should be maintained, as dextrocardia has been associated with respiratory complications secondary to primary ciliary dyskinesia in approximately 25% of patients. Keywords: Anesthesia , dextrocardia , echocardiography , heart septal defects—atrial , situs classification INTRODUCTIONDextrocardia is a congenital abnormality in which the heart is positioned in the right hemithorax. To classify the diagnosis, the situs type must be determined. The word situs refers to the arrangement of structures within the human body, and the 3 types are situs solitus, situs inversus, and situs ambiguus. In dextrocardia with situs solitus, the abdominal organs are in normal configuration, but the heart is located in the right hemithorax.~(1) The majority of patients with this condition have significant cardiac disorders; only 10% of patients with dextrocardia with situs solitus are free from significant cardiac pathology. In contrast, patients with dextrocardia with situs inversus—in which the abdominal organs are reversed or mirrored—have only a 5% to 10% chance of substantial cardiac pathology.~(2) Situs ambiguus is the most severe and disorganized visceral misalignment disorder among the dextrocardia variants.~(3) Patients with the condition are extremely complex anatomically, and one variant, situs ambiguus with polysplenia, has an extremely high mortality rate, with anomalies that include severe pulmonary hypertension.~(4,5)To ensure excellent clinical outcomes, clinicians must be aware of the patient's dextrocardia pathogenesis and use perioperative diagnostic tools such as x-ray, computed tomography (CT), echocardiography, and magnetic resonance imaging to confirm the dextrocardia diagnosis and classify the specific type of dextrocardia. Because dextrocardia with situs solitus primarily affects the cardiovascular system, quantifying the presence or absence of cardiac pathology is important. Even if patients have been previously diagnosed with dextrocardia and are asymptomatic, cardiac consultation for evaluation and a thorough medical history are necessary. The major concern for asymptomatic patients is the diagnosis of congenitally corrected transposition of the great arteries (ccTGA). If the diagnosis of ccTGA is made by echocardiography, further investigation is warranted to rule out increased ventricular end-diastolic pressures or intracardiac shunts.~(6) Patients who are pregnant should have abdominal imaging performed prior to delivery to rule out situs inversus secondary to aortocaval compression mismanagement.~(7) Aortocaval compression is a common occurrence during pregnancy, and delineation of anatomy will help define positioning or uterine displacement to avoid or treat this phenomenon.Dextrocardia alone rarely affects airway pathology, but when dextrocardia is diagnosed as part of situs inversus, the patient's chance of having primary ciliary dyskinesia or Kartagener syndrome is 25%.~(8) When caring for patients with Kartagener syndrome, pulmonary complications are a primary concern. These patients should have a pulmonary consultation prior to any scheduled surgery to ensu